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1.
PLoS One ; 16(6): e0252376, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34133451

RESUMEN

Based on 550 metal analyses, this study sheds decisive light on how the Nordic Bronze Age was founded on metal imports from shifting ore sources associated with altered trade routes. On-and-off presence of copper characterised the Neolithic. At 2100-2000 BC, a continuous rise in the flow of metals to southern Scandinavia begins. First to arrive via the central German Únetician hubs was high-impurity metal from the Austrian Inn Valley and Slovakia; this was complemented by high-tin British metal, enabling early local production of tin bronzes. Increased metal use locally fuelled the leadership competitions visible in the metal-led material culture. The Únetice downfall c.1600 BC resulted for a short period in a raw materials shortage, visible in the reuse of existing stocks, but stimulated direct Nordic access to the Carpathian basin. This new access expedited innovations in metalwork with reliance on chalcopyrite from Slovakia, as well as opening new sources in the eastern Alps, along an eastern route that also conveyed Baltic amber as far as the Aegean. British metal plays a central role during this period. Finally, from c.1500 BC, when British copper imports ceased, the predominance of novel northern Italian copper coincides with the full establishment of the NBA and highlights a western route, connecting the NBA with the southern German Tumulus culture and the first transalpine amber traffic.


Asunto(s)
Arqueología/economía , Arqueología/métodos , Metales/economía , Austria , Países Bálticos , Cobre/economía , Humanos , Italia , Países Escandinavos y Nórdicos , Eslovaquia
2.
J Fluoresc ; 30(3): 695-702, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32382993

RESUMEN

A simple and selective 'turn-on' fluorescence sensor have been developed for the determination of xanthine (XA) based on glutathione (GSH) capped copper nanoclusters (CuNCs) as the fluorescent probe. The proposed sensor possess several advantages such as sensitivity, short analysis time and requires no sample pretreatment. The conditions for the performances of the sensor have been optimized and good linear relationship was obtained between concentration and relative fluorescence intensity in the concentration range 9.0[Formula: see text]10-3 M to 8.0[Formula: see text]10-5 M with a detection limit 6.0[Formula: see text]10-6 M. The mechanism behind the fluorescence enhancement may be ascribed to the binding of XA on the surface of GSH CuNCs. The sensor have been successfully applied to determine XA in spiked physiological samples.


Asunto(s)
Complejos de Coordinación/química , Cobre/química , Colorantes Fluorescentes/química , Glutatión/química , Xantina/análisis , Complejos de Coordinación/economía , Cobre/economía , Análisis Costo-Beneficio , Colorantes Fluorescentes/economía , Glutatión/economía , Tamaño de la Partícula , Espectrometría de Fluorescencia/economía , Propiedades de Superficie , Xantina/economía
3.
Biol Trace Elem Res ; 195(2): 417-426, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31486014

RESUMEN

The pressed powder sample is a common method for elemental analysis using X-ray fluorescence analysis whereas suitable light hydrocarbon materials should be added to the sample as a binder. The present study demonstrates the applicability of using different commercial binders for elemental analysis of urinary stone samples. In order to confirm the obtained results, a comparison with pure chemical grade binders was presented. Different commercial and pure binders were tested for quantitative elemental analysis of urinary stones, namely, cellulose, starch, wax, and urea. Energy dispersive X-ray fluorescence (EDXRF) was used for elemental analysis. Differential thermal analysis was used to estimate the loss on ignition (LOI) in the urinary stone samples. The signal to background ratios (I/IB) of the different detected elements in the commercial and pure binders were calculated, compared, and studied at eight different photon energies starting from 2.5 up to 37 keV. Standard-less quantitative analysis method based on the fundamental parameter approach was applied for elemental analysis of selected urinary stones. The commercial and low-cost binders could be an excellent alternative binder for urinary stone analysis using energy dispersive X-ray fluorescence. The commercial binders could provide an advantage as pure chemical grade binders or even better especially at photon energy higher than 10 keV. The best commercial binder candidate was found to be the wax. The quantitative analysis results using commercial and pure chemical grade binders give good agreement results, which indicate the applicability of commercial binders for quantitative elemental analysis of urinary stones in the form of pressed powder samples.


Asunto(s)
Aluminio/análisis , Celulosa/análisis , Cobre/análisis , Paladio/análisis , Cálculos Urinarios/diagnóstico , Aluminio/economía , Celulosa/economía , Cobre/economía , Costos y Análisis de Costo , Fluorescencia , Humanos , Paladio/economía , Espectrometría por Rayos X , Rayos X
4.
Rev. argent. microbiol ; 51(1): 56-65, mar. 2019. ilus, graf, tab
Artículo en Inglés | LILACS | ID: biblio-1003281

RESUMEN

Thermoacidophiles can exist in a state of dormancy both in moderate temperatures and even in cold conditions in heap leaching. Sulphide mineral ores such as chalcopyrite produce sulfuric acid when exposed to the air and water. The produced sulfuric acid leads to the decrease of pH and exothermic reactions in heap leaching causing the temperature to increase up to 55 °C and the activation of thermoacidophilic microorganisms. The aim of the present study was to isolate indigenous extreme thermoacidophilic microorganisms at ambient temperature from Sarcheshmeh Copper Complex, to adapt them to the high pulp density of a chalcopyrite concentrate, and to determine their efficiency in chalcopyrite bioleaching in order to recover copper. In this study samples were collected at ambient temperature from Sarcheshmeh Copper Complex in Iran. Mixed samples were inoculated into the culture medium for enrichment of the microorganisms. Pure cultures from these enrichments were obtained by subculture of liquid culture to solid media. Morphological observation was performed under the scanning electron microscope. Isolates were adapted to 30% (w/v) pulp density. For the bioleaching test, the experiments were designed with DX7 software. Bioleaching experiments were carried out in Erlenmeyer flasks and a stirred tank reactor. The highest copper recovery in Erlenmeyer flasks was 39.46% with pulp 15%, inoculums 20%, size particle 90 pm and 160 rpm. The lowest recovery was 3.81% with pulp 20%, inoculums 20%, size particle 40 pm and 140 rpm after 28 days. In the reactor, copper recovery was 32.38%. Bioleaching residues were analyzed by the X-ray diffraction (XRD) method. The results showed no jarosite (KFe3(SO4)2(OH)6) had formed in the bioleaching experiments. It seems that the antagonistic reactions among various species and a great number of planktonic cells in Erlenmeyer flasks and the stirred tank reactor are the reasons for the low recovery of copper in our study.


Los microorganismos termoacidófilos pueden estar en estado latente tanto a temperatura moderada como baja, en lixiviación en pilas. Los minerales sulfurosos, como la calcopirita, producen ácido sulfúrico cuando se exponen al aire y al agua. El ácido sulfúrico producido conduce a la disminución del pH y a reacciones exotérmicas durante la lixiviación en pilas, lo que hace que la temperatura aumente hasta 55 °C y se activen los microorganismos termoacidófilos. El objetivo del presente estudio fue aislar del complejo de cobre Sarchesh-meh (Irán) microorganismos termoacidófilos extremos que proliferan a temperatura ambiente e investigar su adaptación a la alta densidad de pulpa del concentrado de calcopirita, así como su eficiencia para biolixiviarese mineral, con el objeto de recuperar el cobre. Se recogieron muestras a temperatura ambiente del citado complejo, y luego muestras mixtas se inocularon en un medio de cultivo de enriquecimiento. A partir de estos enriquecimientos, mediante el subcultivo del cultivo líquido a medio sólido, se obtuvieron cultivos puros. La observación morfológica se realizó bajo microscopio electrónico de barrido. Los aislados estaban adaptados al 30% p/v de densidad de pulpa. Para la prueba de biolixiviación, los experimentos fueron diseñados con el software DX7. Los experimentos de biolixiviación se llevaron a cabo en Erlenmeyers y en un reactor tanque con agitación. La mayor recuperación de cobre en los Erlenmeyers fue del 39,46% y se obtuvo con la pulpa al 15%, un inóculo del 20%, un tamaño de partícula de 90 µm y una agitación de 160 rpm. La menor recuperación fue del 3,81% y se obtuvo con la pulpa al 20%, un inóculo del 20%, un tamaño de partícula de 40 µm y una agitación de 140 rpm, después 28 días. En el reactor, la recuperación del cobre fue del 32,38%. El análisis de difracción de rayos X (XRD) no mostró que se formara jarosita (KFe3-#91;SO4-#93;2-#91;OH-#93;6) en los experimentos de biolixiviación. Dicha técnica sirve para determinar la estructura cristalina de una sustancia desconocida. Al parecer, las reacciones antagónicas entre las diversas especies y el mayor número de células planctónicas en los Erlenmeyers y en el reactor fueron las causas de la baja recuperación de cobre observada en este estudio.


Asunto(s)
Percolación/análisis , Reacciones Químicas/análisis , Cobre/economía , Causalidad , Adaptación a Desastres , Concentración de Iones de Hidrógeno
6.
Environ Sci Technol ; 49(11): 6430-7, 2015 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-25927890

RESUMEN

Two approaches are adopted to characterize the comprehensive pattern of the copper in-use stocks in China. The top-down results indicate that both the total amount and the per capita quantity of the stocks have exhibited a significant and increasing trend for the past 60 years, especially since 2000. The top-down results show that the copper stocks increased from a negligible level of less than 1 kg/capita in 1952 to 44 kg/capita in 2012. The total stocks in 2012 are estimated to be 60 Mt by a top-down approach or 48 Mt by a bottom-up calculation. The bottom-up method determines that the largest reservoir is the infrastructure sector, which accounts for approximately 58% of the total stocks. The spatial pattern indicates that the copper in-use stocks are predominately spatially distributed in the eastern regions of China, a feature that is obviously different from the geographical distribution of the primary resources. Analysis on the prospects of stocks shows both the total magnitude and per capita value will continuously increase in the following decade, and enter a relatively stable stage in around 2030, with a maximum value of 106 kg/capita. The results improve the knowledge about closing copper cycles.


Asunto(s)
Cobre/análisis , Cobre/economía , China , Materiales de Construcción , Transportes
7.
Jpn J Vet Res ; 61 Suppl: S23-32, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23631149

RESUMEN

The Katanga province is well known for its copper and cobalt reserves. During the early 2000s a boom of mining projects in Katanga brought again hope for better future to Congolese people. The paper aims to evaluate the impact of recent production recovery on economy and environment. We collected primary and secondary sources on copper industry for economic analysis. We use results of laboratory analysis conducted at the Congolese Office of Control by provincial division of environment for toxicological analysis. The comparison of heavy metal concentration to standards shows that mining industry is the main source of environmental pollution in Katanga. Copper industry generates income for economic growth of the region.


Asunto(s)
Cobre/química , Cobre/toxicidad , Minería/economía , Contaminantes del Suelo/química , Contaminantes Químicos del Agua/química , Animales , Congo , Cobre/economía , Peces , Ríos/química , Contaminantes del Suelo/economía , Contaminantes del Suelo/toxicidad , Contaminantes Químicos del Agua/economía , Contaminantes Químicos del Agua/toxicidad
8.
J Health Econ ; 31(6): 797-812, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22940637

RESUMEN

Existing studies suggest that individual and household level economic shocks affect the demand for and supply of risky sex. However, little evidence exists on the effects of an aggregate shock on equilibrium risky sexual behavior. This paper examines the effects of the early twenty-first century copper boom on risky sexual behavior in Zambian copper mining cities. The results suggest that the copper boom substantially reduced rates of transactional sex and multiple partnerships in copper mining cities. These effects were partly concentrated among young adults and copper boom induced in-migration to mining cities appears to have contributed to these reductions.


Asunto(s)
Cobre/economía , Minería/economía , Asunción de Riesgos , Conducta Sexual/estadística & datos numéricos , Población Urbana , Adolescente , Adulto , Ciudades , Femenino , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Factores Socioeconómicos , Población Urbana/estadística & datos numéricos , Adulto Joven , Zambia
9.
Environ Sci Technol ; 46(2): 1071-8, 2012 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-22192049

RESUMEN

Because modern technology depends on reliable supplies of a wide variety of materials, and because of increasing concern about those supplies, a comprehensive methodology has been created to quantify the degree of criticality of the metals of the periodic table. In this paper, we apply this methodology to the elements of the geological copper family: Cu, As, Se, Ag, Te, and Au. These elements are technologically important, but show a substantial variation in different factors relating to their supply risk, vulnerability to supply restriction, and environmental implications. Assessments are made on corporate, national, and global levels for year 2008. Evaluations of each of the multiple indicators are presented and the results plotted in "criticality space", together with Monte Carlo simulation-derived "uncertainty cloud" estimates for each of the aggregated evaluations. For supply risk over both the medium term and long term, As is the highest risk of the six metals, with Se and Ag nearly as high. Gold has the most severe environmental implications ranking. Vulnerability to supply restriction (VSR) at the corporate level for an invented solar cell manufacturing firm shows Se, Te, and Cu as approximately equal, Cu has the highest VSR at the national level, and Cu and Au have the highest VSRs at the global level. Criticality vector magnitudes are greatest at the global level for As (and then Au and Ag) and at the national level for As and Au; at the corporate level, Se is highest with Te and Cu lower. An extension of this work, now in progress, will provide criticality estimates for several different development scenarios for the period 2010-2050.


Asunto(s)
Cobre/economía , Cobre/provisión & distribución , Industrias/economía , Industrias/métodos , Arsénico/provisión & distribución , Cobre/clasificación , Modelos Teóricos , Selenio/provisión & distribución , Telurio/provisión & distribución
10.
Commun Agric Appl Biol Sci ; 75(4): 725-32, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21534483

RESUMEN

In organic farming copper is one of the few fungicides that can be used and the only effective against downy mildew. Due to the problems of environmental impact associated with the use of this heavy metal, the European Union decided to restrict its use (Annex II Regulation EC n. 889/2008). In order to assess the possibility of replacing the copper or reduce the quantities used, we tested natural products and low rate copper formulations in field trials. The anti-downy mildew activity of these formulations has been studied in an organic vineyard. During the two years of activity we also estimated the economic cost of use of the products to assess their possible use in agricultural practice.


Asunto(s)
Productos Biológicos/farmacología , Cobre/farmacología , Fungicidas Industriales/farmacología , Oomicetos/efectos de los fármacos , Enfermedades de las Plantas/economía , Enfermedades de las Plantas/microbiología , Vitis/microbiología , Productos Biológicos/economía , Cobre/economía , Fungicidas Industriales/economía , Oomicetos/fisiología
11.
Environ Sci Technol ; 41(19): 6649-56, 2007 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-17969676

RESUMEN

Many authors suggest that market forces are inadequate to successfully manage the problems of resource availability and use. The fundamental question is whether these inadequacies are intrinsic to the market or if they arise from a failure of firms to detect and respond to subtle market signals. This paper explores the latter by describing (1) mechanisms that can limit materials availability, (2) effects of such limits on the firm, (3) preliminary metrics to diagnose these risks, and (4) strategies to reduce a firm's risk exposure. Case analyses of two materials systems are used to suggestthat private firm interests, when properly informed, can motivate strategies that drive toward sustainable materials use. These strategies include (1) improving production efficiency, (2) developing technology to use more sustainable substitute materials, and (3) facilitating a more effective materials recycling infrastructure.


Asunto(s)
Comercio , Conservación de los Recursos Naturales , Cobalto/economía , Cobre/economía
13.
Proc Natl Acad Sci U S A ; 103(5): 1209-14, 2006 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-16432205

RESUMEN

The relative proportions of metal residing in ore in the lithosphere, in use in products providing services, and in waste deposits measure our progress from exclusive use of virgin ore toward full dependence on sustained use of recycled metal. In the U.S. at present, the copper contents of these three repositories are roughly equivalent, but metal in service continues to increase. Providing today's developed-country level of services for copper worldwide (as well as for zinc and, perhaps, platinum) would appear to require conversion of essentially all of the ore in the lithosphere to stock-in-use plus near-complete recycling of the metals from that point forward.


Asunto(s)
Cobre/química , Metales/química , Conservación de los Recursos Naturales , Cobre/economía , Electrónica , Plomo/química , Materiales Manufacturados/economía , Minería/economía , Níquel/química , Fotograbar , Platino (Metal)/química , Plata/química , Acero Inoxidable/química , Estaño/química , Zinc/química
14.
J Environ Manage ; 78(2): 138-48, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16095805

RESUMEN

In mine water pollution abatement, it is commonly assumed that known mine waste sites are the major pollution sources, thus neglecting the possibility of significant contribution from other old and diffuse sources within a catchment. We investigate the influence of different types of pollution source uncertainty on cost-effective allocation of abatement measures for mine water pollution. A catchment-scale cost-minimization model is developed and applied to the catchment of the river Dalälven, Sweden, in order to exemplify important effects of such source uncertainty. Results indicate that, if the pollution distribution between point and diffuse sources is partly unknown, downstream abatement measures, such as constructed wetlands, at given compliance boundaries are often cost-effective. If downstream abatement measures are not practically feasible, the pollution source distribution between point and diffuse mine water sources is critical for cost-effective solutions to abatement measure allocation in catchments. In contrast, cost-effective solutions are relatively insensitive to uncertainty in total pollutant discharge from mine water sources.


Asunto(s)
Residuos Industriales , Minería , Contaminación Química del Agua/economía , Cadmio/análisis , Cadmio/economía , Cobre/análisis , Cobre/economía , Costos y Análisis de Costo , Modelos Teóricos , Ríos , Suecia , Incertidumbre , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/economía , Contaminación Química del Agua/prevención & control , Abastecimiento de Agua , Zinc/análisis , Zinc/economía
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